92 Colour and Other Characters in Pigeons 



produced, 8 white, 1 red, aud 14 smoky. The red had some primaries 

 and tail feathers white. The dark F„ were not so uniform as those 

 of i'l ; 4 of them had no white feathers, the remaining 10 liad the 

 white distributed much as in F^. But the ground colour of these birds 

 varied considerably from an almo.st uniform smoky brown, with a tinge 

 of red in many of the feathers, to a dark smoky blue-grey, with quite 

 distinct bars across the wings and at the tip of the tail. Only two of 

 the ]4 dark birds had conspicuous wing-bars, but they were indicated 

 in several others. The tail featiiers varied in number from 12 to 16 ; 

 none of the F.^ young showed anything that could be called a fantail. 

 The presence or absence of the oil-gland at the base of the tail was 

 unfortimately not always recorded ; it is absent in the Fantail, but was 

 present in all the F^ birds which were examined. In F„ it was recorded 

 as absent in 4, present in 10 ; of the latter one had an extremely small 

 oil-gland and another had a double one. The fact that the oil-gland 

 was found in all the F^ birds examined, and in 10 out of 14 in F^, 

 suggests that it behaves as a dominant Mendelian character. 



In addition to the pairings between F^ birds, an ^i J" was paired 

 with a White Fantail J , giving one pure white and two smoky young. 

 Both the latter had some white, distributed as in the F^ birds, and one 

 had dark wing-bars. 



In order to determine whether a white bird can bear the determinant 

 for one or another colour, as happens in mammals, one of the white F„ 

 young (cf) was paired with a Red (rose-wing) $. The i-ose-wing is like 

 the original Red Tumbler described above, except that it has a patch of 

 white feathers near the base of each wing. The extracted white (in ^2 

 from White Fantail x Red Tumbler) paired with the rose-wing gave 

 7 reds, all with a varying amount of white, and 3 dark like the original 

 F, birds. 



Since the original cross between white and red gave in F^ uniformly 

 dark birds, which when paired together gave among their coloured 

 offspring both red and dark, and since a white F^ bird crossed with red 

 gave both red and dark, it may be assumed that the original white 

 fantail bore one kind of colour determinant, which on meeting red gave 

 smoky (F^), but that the F,. white was heterozygous for colour 

 determinants, bearing red as well as another. Since the dark birds 

 in Fo were not uniform, but in some cases were bluish with wing-bars, 

 it seems probable that the determinant borne by the original fantail 

 was for ' blue ' (slate-grey with dark wing-bars), and that this meeting 

 red gives the smoky heterozygote described. 



